code: def __str__(self):
      return f"DummyEnvironment({self.version!r}, {self.domains!r})"
  
imports: import json
  import warnings
  from io import BytesIO
  import pytest
  from docutils import frontend, utils
  from docutils.parsers import rst
  from sphinx.search import IndexBuilder
label_desc: Use image node_id 3 for calling the DummyEnvironment obj's underlying member method code with example usage: obj.__str__() and returns: str, self, str, self, str